Calories burned during swimming
Swimming easy laps burns roughly 180–245 kcal in half an hour for a 70 kg person — a range, because stroke, technique and pace swing it widely. Efficient front crawl at speed sits near the top; a relaxed breaststroke lower. Water also makes perceived effort deceptive. Use your own weight and time below for a closer estimate.
Enter your weight and how long you moved — the estimate comes back as a range, the same way our diary does it.
| Weight | 15 min | 30 min | 45 min | 60 min |
|---|---|---|---|---|
| 50 kg | 65–88 | 129–175 | 194–263 | 259–350 |
| 60 kg | 78–105 | 155–210 | 233–315 | 311–420 |
| 70 kg | 91–123 | 181–245 | 272–368 | 362–490 |
| 80 kg | 104–140 | 207–280 | 311–420 | 414–560 |
| 90 kg | 116–158 | 233–315 | 349–473 | 466–630 |
| 100 kg | 129–175 | 259–350 | 388–525 | 518–700 |
| 110 kg | 142–193 | 285–385 | 427–578 | 569–770 |
Each cell is a range (±15%). Read down for your weight, across for your time. These are population estimates, not a measurement of you.
| Intensity | 30 min | 60 min |
|---|---|---|
| Swimming, leisurely (no laps) · 6 MET | 187–254 | 375–507 |
| Swimming laps, slow (recreational) · 5.8 MET | 181–245 | 362–490 |
| Swimming laps, fast (vigorous) · 9.8 MET | 306–414 | 612–828 |
| Water aerobics · 5.5 MET | 172–232 | 344–465 |
A 30-minute session at 70 kg — the pace changes the cost far more than a few kilos do.
Energy cost from the 2024 Adult Compendium of Physical Activities (Herrmann, Willis, Ainsworth et al.). kcal = MET × 3.5 × weight(kg) ÷ 200 × minutes; we show it as a band because a MET is a population average. Why a range, not one number →
How many calories does swimming burn?
It depends on your weight, how long you keep it up and — a lot — your pace and fitness, so there is no single true number. The table and the calculator give a range for your weight and time. Two people of the same weight can differ by 15–25% at the same activity.
Why show a range instead of one number?
Because a MET value is a population average. Your real burn shifts with fitness, technique, terrain and how hard you actually went. A single "347 kcal" reads as precise when it isn't — the honest answer is a band, and that is what we show.
Do calories burned mean I can eat that much back?
No. This is an estimate of energy spent, not calories you have to "earn" or a licence to eat more. Movement is worth doing for its own sake. If you track a day's balance, use the range — never treat the top of it as exact.
Where do the numbers come from?
MET values from the 2024 Adult Compendium of Physical Activities, a public reference cited by researchers. We apply the standard MET formula and widen it into a ±15% band (±25% for strength work, which a MET barely captures).